AMMONIA WITH CARBONIC ACID. 99 



son why they can both combine in the most varied proportions. 

 The number of these combinations is in fact surprising. I have 

 prepared several of them, the existence of which was previously 

 unknown. It would, however, have been easy for me to have 

 greatly increased their number by further examination, but I 

 have contented myself with indicating the possibility of the ex- 

 istence of a great number of such combinations, since their pre- 

 paration and examination would occasion more trouble than the 

 subject appeared worthy of. 



The reason of the great number of these combinations arises 

 less fi'om the weak affinity which carbonic acid has for ammonia, 

 than from the circumstance that the various combinations ha\'e 

 a great tendency to form double salts with each other. I have 

 attempted to consider several salts which carbonic acid forms 

 with ammonia as double salts combined in certain proportions, 

 by which the number of the more simple combinations is hmited. 



Hitherto we were acquainted with onlj'^ the following com- 

 binations of carbonic acid with ammonia in a sohd state: 1. 

 the anhydrous neutral carbonate of ammonia, NH ^ + C j 2. the 

 sesquicarbonate of ammonia, 2 NH ^ + 3 C + 2 H, or rather 

 the sesquicarbonate of the oxide of ammonium, 2 NH* + 3 C • 

 and 3. the bicarbonate of ammonia, NH ^ + 2 C + 2 H or 

 NH '' + 2 C + H. — 



With respect to the analysis of the combinations of the car- 

 bonic acid with ammonia, the proportions of the ammonia and 

 carbonic acid were determined directly, the water by the loss. 



The determination of the ammonia may be effected with the 

 greatest accuracy. The carbonate of ammonia was placed in a 

 vessel which could be closed with a stopper, and a mixture of 

 equal parts of muriatic acid and alcohol added ; after the com- 

 plete disengagement of all the carbonic acid, the solution was 

 diluted by the addition of very strong alcohol (90 — 95 p. c). 

 Upon this an excess of a solution of chloride of platina and 

 then aether to nearly the amount of one fourth the volume of the 

 alcohol, was added. The ammonio-chloride of platina is quite 

 insoluble in a mixtiu-e of strong alcohol and aether, and may be 

 collected without loss. I let it completely settle at the bottom 

 of the stoppered bottle for twelve hours, and washed it out with a 

 mixture of alcohol and aether. After desiccation it was cautiously 

 exposed to ignition in a platina crucible. The salt was placed 

 with the filtering paper in the crucible, and not as is usually done 



G 2 



